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Nanotechnology will affect our lives tremendously over the next decade in very different fields, including medicine and pharmacy. Transfer of materials into the nanodimension changes their physical properties which were used in pharmaceutics to develop a new innovative formulation principle for poorly soluble drugs: the drug nanocrystals. The drug nanocrystals do not belong to the future; the first products are already on the market. The industrially relevant production technologies, pearl milling and high pressure homogenization, are reviewed. The physics behind the drug nanocrystals and changes of their physical properties are discussed. The marketed products are presented and the special physical effects ofnanocrystals explained which are utilized in each market product. Examples of products in the development pipelines (clinical phases) are presented and the benefits for in vivo administration of drug nanocrystals are summarized in an overview.

A mechanism for phosphoinositide conversion at endosomes to enable exit from the endosomal system, suggesting that defective phosphoinositide conversion at endosomes underlies X-linked centronuclear myopathy. Phosphoinositide conversion during endosome exit Directional membrane traffic requires regulated conversion of phosphoinositides (PIs) — membrane phospholipids that act as determinants of membrane identity — by PI metabolizing enzymes. Volker Haucke and co-workers studied the mechanism of PI identity shifts during trafficking from the endosomal system — defined by phosphatidylinositol 3-phosphate (PI(3)P) — to the secretory compartments and the plasma membrane, dominated by phosphatidylinositol 4-phosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P 2 ). The authors find that endosomal cargo en route to intracellular destinations can change direction and make its way back to the cell surface by the action of two enzymes. Specifically, PI(3)P on the membrane of these compartments is hydrolysed by the phosphatase MTM1, an enzyme whose loss of function leads to X-linked centronuclear myopathy in humans. This hydrolysis of PI(3)P is accompanied by the generation of PI(4)P through the action of phosphatidylinositol 4-kinase, as well as the recruitment of the exocyst tethering complex to enable subsequent membrane fusion. Phosphoinositides are a minor class of short-lived membrane phospholipids that serve crucial functions in cell physiology ranging from cell signalling and motility to their role as signposts of compartmental membrane identity 1 , 2 . Phosphoinositide 4-phosphates such as phosphatidylinositol 4-phosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P 2 ) are concentrated at the plasma membrane, on secretory organelles 3 , and on lysosomes 4 , whereas phosphoinositide 3-phosphates, most notably phosphatidylinositol 3-phosphate (PI(3)P) 5 , are a hallmark of the endosomal system 1 , 2 . Directional membrane traffic between endosomal and secretory compartments, although inherently complex, therefore requires regulated phosphoinositide conversion. The molecular mechanism underlying this conversion of phosphoinositide identity during cargo exit from endosomes by exocytosis is unknown. Here we report that surface delivery of endosomal cargo requires hydrolysis of PI(3)P by the phosphatidylinositol 3-phosphatase MTM1, an enzyme whose loss of function leads to X-linked centronuclear myopathy (also called myotubular myopathy) in humans 6 . Removal of endosomal PI(3)P by MTM1 is accompanied by phosphatidylinositol 4-kinase-2α (PI4K2α)-dependent generation of PI(4)P and recruitment of the exocyst tethering complex to enable membrane fusion. Our data establish a mechanism for phosphoinositide conversion from PI(3)P to PI(4)P at endosomes en route to the plasma membrane and suggest that defective phosphoinositide conversion at endosomes underlies X-linked centronuclear myopathy caused by mutation of MTM1 in humans.

Phosphoinositides are important regulators of intracellular membrane traffic, and although the role of PI(4,5)P 2 has been well characterised, the function of PI(3,4)P 2 remains unclear; here the formation of PI(3,4)P 2 by the class II phosphatidylinositol-3-kinase C2α enzyme is shown to control clathrin-mediated endocytosis. Endocytosis control by lipid switch Phosphoinositides are important regulators of intracellular membrane traffic. Although the role of phosphatidylinositol-4,5-bisphosphate has been well characterized, that of phosphatidylinositol-3,4-bisphosphate (PI(3,4)P 2 ) remains unclear. In this study, Volker Haucke and colleagues show that formation of PI(3,4)P 2 by the class II phosphatidylinositol-3-kinase C2α (PI(3)K C2α) enzyme spatiotemporally controls clathrin-mediated endocytosis. These findings present a novel function of PI(3,4)P 2 in membrane traffic. Phosphoinositides serve crucial roles in cell physiology, ranging from cell signalling to membrane traffic 1 , 2 . Among the seven eukaryotic phosphoinositides the best studied species is phosphatidylinositol-4,5-bisphosphate (PI(4,5)P 2 ), which is concentrated at the plasma membrane where, among other functions, it is required for the nucleation of endocytic clathrin-coated pits 3 , 4 , 5 , 6 . No phosphatidylinositol other than PI(4,5)P 2 has been implicated in clathrin-mediated endocytosis, whereas the subsequent endosomal stages of the endocytic pathway are dominated by phosphatidylinositol-3-phosphates(PI(3)P) 7 . How phosphatidylinositol conversion from PI(4,5)P 2 -positive endocytic intermediates to PI(3)P-containing endosomes is achieved is unclear. Here we show that formation of phosphatidylinositol-3,4-bisphosphate (PI(3,4)P 2 ) by class II phosphatidylinositol-3-kinase C2α (PI(3)K C2α) spatiotemporally controls clathrin-mediated endocytosis. Depletion of PI(3,4)P 2 or PI(3)K C2α impairs the maturation of late-stage clathrin-coated pits before fission. Timed formation of PI(3,4)P 2 by PI(3)K C2α is required for selective enrichment of the BAR domain protein SNX9 at late-stage endocytic intermediates. These findings provide a mechanistic framework for the role of PI(3,4)P 2 in endocytosis and unravel a novel discrete function of PI(3,4)P 2 in a central cell physiological process.

We have successfully developed curcumin nanosuspension intended for oral delivery. The main purpose is to improve bioavailability through enhancing its solubility. The nanoparticles were stabilized using various stabilizers, including polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), sodium carboxymethylcellulose (Na-CMC), d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), and sodium dodecyl sulfate (SDS). The average diameter of particles, microscopic appearance, and sedimentation of each preparation was observed and compared. Each stabilizer demonstrated a different degree of inhibition of particle aggregation under electrolyte-containing simulated gastrointestinal (GIT) fluid. Non-ionic stabilizers (PVA, PVP, and TPGS) were shown to preserve the nanosuspension stability against electrolytes. In contrast, strong ionic surfactants such as SDS were found to be very sensitive to electrolytes. The results can provide useful information for the formulators to choose the most suitable stabilizers by considering the nature of stabilizers and physiological characteristics of the target site of the drug.

Coffee silverskin is a byproduct of the coffee industry, appearing in large quantities during the roasting step. In this work, a sober and simple water process is proposed, using extractions cycles, to produce valuable products including (a) an extract rich in caffeine, (b) possibly pure caffeine, and (c) insoluble fibers. The hypothetical number of necessary cycles was calculated and compared to the number of cycles used experimentally. Two types of cycles, with and without water compensation, were compared for their water consumption and the amount of caffeine extracted. The use of cycles, with the resulting product from a previous extraction as a solvent for fresh biomass, drove a significant rise in the content of caffeine determined by a UV–visible detector with a spectrophotometer and ultra-performance liquid chromatography (UPLC). After 11 extraction cycles with water compensation, we obtained an extract 4.5 times more concentrated in caffeine (4.25 mg/mL) than after a single extraction (1.03 mg/mL).

Phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] is essential for exocytosis. Classical ways of manipulating PI(4,5)P2 levels are slower than its metabolism, making it difficult to distinguish effects of PI(4,5)P2 from those of its metabolites. We developed a membrane-permeant, photoactivatable PI(4,5)P2, which is loaded into cells in an inactive form and activated by light, allowing sub-second increases in PI(4,5)P2 levels. By combining this compound with electrophysiological measurements in mouse adrenal chromaffin cells, we show that PI(4,5)P2 uncaging potentiates exocytosis and identify synaptotagmin-1 (the Ca2+ sensor for exocytosis) and Munc13-2 (a vesicle priming protein) as the relevant effector proteins. PI(4,5)P2 activation of exocytosis did not depend on the PI(4,5)P2-binding CAPS-proteins, suggesting that PI(4,5)P2 uncaging may bypass CAPS-function. Finally, PI(4,5)P2 uncaging triggered the rapid fusion of a subset of readily-releasable vesicles, revealing a rapid role of PI(4,5)P2 in fusion triggering. Thus, optical uncaging of signaling lipids can uncover their rapid effects on cellular processes and identify lipid effectors. Cells in our body communicate by releasing compounds called transmitters that carry signals from one cell to the next. Packages called vesicles store transmitters within the signaling cell. When the cell needs to send a signal, the vesicles fuse with the cell's membrane and release their cargo. For many signaling processes, such as those used by neurons, this fusion is regulated, fast, and coupled to the signal that the cell receives to activate release. Specialized molecular machines made up of proteins and fatty acid molecules called signaling lipids enable this to happen. One signaling lipid called PI(4,5)P2 (short for phosphatidylinositol 4,5-bisphosphate) is essential for vesicle fusion as well as for other processes in cells. It interacts with several proteins that help it control fusion and the release of transmitter. While it is possible to study the role of these proteins using genetic tools to inactivate them, the signaling lipids are more difficult to manipulate. Existing methods result in slow changes in PI(4,5)P2 levels, making it hard to directly attribute later changes to PI(4,5)P2. Walter, Müller, Tawfik et al. developed a new method to measure how PI(4,5)P2 affects transmitter release in living mammalian cells, which causes a rapid increase in PI(4,5)P2 levels. The method uses a chemical compound called “caged PI(4,5)P2” that can be loaded into cells but remains undetected until ultraviolet light is shone on it. The ultraviolet light uncages the compound, generating active PI(4,5)P2 in less than one second. Walter et al. found that when they uncaged PI(4,5)P2 in this way, the amount of transmitter released by cells increased. Combining this with genetic tools, it was possible to investigate which proteins of the release machinery were required for this effect. The results suggest that two different types of proteins that interact with PI(4,5)P2 are needed: one must bind PI(4,5)P2 to carry out its role and the other helps PI(4,5)P2 accumulate at the site of vesicle fusion. The new method also allowed Walter et al. to show that a fast increase in PI(4,5)P2 triggers a subset of vesicles to fuse very rapidly. This shows that PI(4,5)P2 rapidly regulates the release of transmitter. Caged PI(4,5)P2 will be useful to study other processes in cells that need PI(4,5)P2, helping scientists understand more about how signaling lipids control many different events at cellular membranes.

Rutin is a well-known antioxidant from the group of flavonoids. Its use in cosmetic dermal products is, however, limited due to its poor water solubility. In order to increase rutin saturation solubility and improve the diffusion to the skin, rutin nanocrystals were produced by the smartCrystal process, e.g., bead milling followed by high pressure homogenization. Rutin nanocrystals were further incorporated into hydroxypropyl cellulose (HPC) gel and its long-term stability was assessed. Determination of the antioxidant activity was made by the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay for these formulations: rutin nanocrystals (mean size 300 nm), rutin raw drug powder (mean size 33 μm) and commercial product. Furthermore, the skin penetration profile of rutin was investigated by the tape-stripping method on porcine skin. This study demonstrated that rutin nanocrystal gel had the highest neutralizing activity (90%), followed by a commercial product and rutin raw drug powder. According to the skin study, rutin nanocrystals penetrated to the deeper layers of the stratum corneum, the horny layer of the skin.

Inhibition of the phospholipid phosphatase and tumor suppressor PTEN leads to excessive polarized cell growth during directed cell migration and neurite outgrowth. These processes require the precise regulation of both the actin and microtubule cytoskeleton. While PTEN is known to regulate actin dynamics through phospholipid modulation, whether and how PTEN regulates microtubule dynamics is unknown. Here, we show that depletion of PTEN leads to elevated levels of stable and post-translationally modified (detyrosinated) microtubules in fibroblasts and developing neurons. Further, PTEN depletion enhanced axon outgrowth, which was rescued by reducing the level of detyrosinated microtubules. These data demonstrate a novel role of PTEN in regulating the microtubule cytoskeleton. They further show a novel function of detyrosinated microtubules in axon outgrowth. Specifically, PTEN suppresses axon outgrowth by down-regulating the level of detyrosinated microtubules. Our results suggest that PTEN's role in preventing excessive cell growth in cancerous and neurodevelopmental phenotypes is partially exerted by stabilization and detyrosination of the microtubule cytoskeleton.

Background The prevalence of dizziness increases with age. We aimed to determine the point prevalence of dizziness and, in particular, of benign paroxysmal positional vertigo (BPPV) among retirement home residents. Furthermore, we aimed to evaluate the efficacy of a 2-axis turntable based BPPV treatment. Methods We contacted all large retirement homes in or around the city of Zurich (Switzerland). 10 retirement homes (with a total of 536 residents) agreed to participate in this study. 83 rejected inquiries by residents led to a potential study population of 453 residents. After a structured interview evaluating the presence and characteristics of dizziness, all willing patients were tested for positional vertigo and nystagmus on a portable and manually operated 2-axis turntable that was transported to the retirement home. Testing consisted of the Dix-Hallpike and supine roll maneuvers to both sides. Participants were immediately treated with the appropriate liberation maneuver whenever BPPV was diagnosed. Otherwise, taking the resident’s medical history, a neuro-otological bedside examination, and a review of the available medical documentation was used to identify other causes of dizziness. Results Out of the 453 residents, 75 (16.6%; average age: 87.0 years; 68% female) were suffering from dizziness presently or in the recent past and gave their consent to participate in this study. Among the participants tested on the turntable ( n  = 71), BPPV was present in 11.3% (point prevalence). Time-related properties, triggering factors and qualitative attributes of vertigo or dizziness were not significantly different between the dizzy participants with and those without BPPV. In all BPPV patients, appropriate liberation maneuvers were successful. Conclusions BPPV could be demonstrated in about one tenth of retirement home residents with dizziness or recent dizziness. Such point prevalence of BPPV translates to a much higher yearly prevalence if one assumes that BPPV is not present on every day. Our finding suggests that retirement home residents suffering from dizziness should be regularly tested for BPPV and treated with appropriate liberation maneuvers, ideally on turntable to reduce strain. Trial registration ClinicalTrials.gov Identifier NCT03643354 .

This study describes the production of a budesonide nanosuspension by high-pressure homogenization for pulmonary delivery from 40 mL up to 300 mL. The aim was to obtain a nanosuspension that can be nebulized and is also long-term stable. The nanosuspension was produced by high-pressure homogenization. Particle size analysis was performed by laser diffraction and photon correlation spectroscopy. For further particle characterization, zeta potential was determined. To investigate the aerosolization properties, the nanosuspension was nebulized and afterward analyzed on particle size. It was possible to obtain a long-term stable budesonide nanosuspension. Mean particle size of this nanosuspension was about 500-600 nm, analyzed by photon correlation spectroscopy. Analysis by laser diffraction showed that the diameters 95% and 99% were below 3 microm. Budesonide nanosuspension showed a long-term stability; no aggregates and particle growth occurred over the examined period of 1 year. The PCS diameter before and after aerosolization did not change, and the LD diameters increased negligibly, showing the suitability for pulmonary delivery. The scale-up from 40 mL up to 300 mL was performed successfully. High-pressure homogenization is a production method to obtain nanosuspensions with budesonide for pulmonary applica-